The invention relates generally to packaging, and more particularly to forming, filling and sealing of reclosable packaging.
For certain food products, efficiency in packaging and acceptable shelf life can be obtained by hermetically sealing the product in a package in a form/fill/seal (FFS) operation. One prior art FFS operation that has been used commercially for products such as blocks of cheese involves orienting a web of laminated polymeric material horizontally, placing product on the web, wrapping the web upward around both sides of the product to bring the edges together to form a longitudinal fin seal, and subsequently sealing the ends and cutting the finished package from the web. Gas flush techniques are employed to eliminate oxygen from the package interior. Such an operation is illustrated in U.S. Pat. No 3,274,746.
To provide reclosability for packages produced according to the above method, a continuous narrow strip of zipper material may be secured within a continuous longitudinal fold in the web in a roll-to-roll operation, prior to use of the web in the FFS operation. A form/fill/seal operation employing a roll of film with a pre-applied zipper secured within a longitudinal fold in the web is illustrated in U.S. Pat. Nos. 4,589,145 and 4,663,915. One shortcoming of this method is that it is somewhat inefficient in requiring two separate operations to provide the finished package. Also, the roll of package material becomes rather bulky and unwieldy after attachment of the zipper, and is lopsided due to the accumulation of successive layers of zipper material on one side of the roll. This may limit the speed of the FFS apparatus, and further may require more frequent replacement of the rolls of stock than in FFS operations where zippers are not used. There is a need for a more efficient method of providing reclosable packaging in horizontal FFS operations.